Tube making apparatus



April 6, 1937. A. P. DIESCHER 2,075,336

TUBE MAKING APPARATUS Filed May 2, 1936 INVENTOR.

M W ATTORNEYS.

Patented Apr. 6, 1937 UNITED STATES.

PATENT OFFICE TUBE -MAKING APPARATUS August P. Diescher, Pittsburgh, Pa., assignor to Diescher Tube Mills, Inc., Pittsburgh, Pa., a corporation of Delaware ApplicatiouMay z, 1936, Serial No'. 11,523: 2 Claims. (Cl. sly-54) The invention relates to cross-rolling mills for helically acting upon seamless tubular blanks, particularly of steel or other ferrous base metals,

- and contemplates various types of such mills such as those used for reducing the wall thickness of As heretofore used in actual practice, such cross-rolling mills have been constructed and operated as single units with a separate drive for each. It is sometimes desirable to give tubular blanks or tubes two or more passes through cr'ossrolling mills, and in doing this it is desirable to avoid intermediate heating such as would be nec essary if a material amount of time were required to convey blanks from one to another pass, whether the second pass be through the same or through 1 another mill. In the straight rolling of metal, as for example strip metal, it is possible to position a plurality of roll stands so close to each other that the metal is simultaneously in the passes of a plurality of rolls, but, due to the peculiar flow of metal in cross-rolling operations, it is imp'ractical, if not impossible, to so position cross-rolling mills that a tubular blank is simultaneously in two passes.

The object of this invention is to provide a tandem cross-rolling mill for the purpose explained which is economical to build as well as to operate, the mill being equipped with a drive which simplifies the construction and operation of the mill and which facilitates rapid handling of blanks between passes. The invention is somewhat diagrammatically illustrated in the accompanying drawing, of which Fig. 1 is a plan view of a tandem cross-rolling mill and drive for it; Fig. 2 an elevation to enlarged scale of the drive shown in the central portion of Fig. 1, some parts being shown in section; and

Fig. 3 a side view of the'drive shown in Fig. 2,

the plane of view being IlIIlI, Fig. 2.

In the practice of this invention a pair of crossrolling mills are arranged in tandem for successive action upon tubular blanks. These mills may be any of the several types explained above for reducing, elongating, expanding and sinking seamless blanks or tubes. Each mill is provided with a plurality of, preferably two, cross-rolls which may be of any well-known or desired construction, as for example barrel-shape, conical or overlapping disc rolls. Between the two mills indicated by the line there isa power unit with connections extending from it to each mill for properly driving their cross-rolls. In the illustrative embodiment of the invention, it is shown in its applicability to a tandem mill for reducing the wall thickness of and elongating tubular blanks upon cylindrical mandrels which pass through the mills within the blanks. When it is desired to produce tubing having unusually thin walls it is advantageous to eifect the necessary reduction and elongation in a plurality of passes. Also, in the sinking of tubes to reduce their diameters substantial amounts it is desirable to give the tubes a plurality of passes.

Having reference to the embodiment of the invention illustrated in the drawing, a pair 01 cross-rolling mills l and 2 are shown in tandem, each being the. same except for the right and left-hand arrangements of theirdrives. Each includes a pair of barrel-shape cross-rolls 3 having a pair oiv driven guide discs 4 arranged between them, one above and one below the line of pass through the mill. The construction and manner of operating such mills when used for elongating tubular blanks is disclosed in Patent No. 1,870,209, and the method of operating such mills for sinking tubes is disclosed in Patent No. 1,934,844, both to Samuel E. Diescher. It will be understood, however, that the invention contemplates types of cross-rolling mills other than those here illustrated and than those disclosed in these patents. The guide discs 4 of each mill are driven at a relatively high peripheral speed through suitable spindles 5 which connect them to driving motors.

Arranged between the two mills there is a single power unit, which, in the illustrated embodiment of the invention, consists of a gear box 6 equipped with suitable gears adapted to be driven by a motor I. To drive the cross-rolls with a minimum loss of power the gear box preferably extends directly across the line of pass between the mills, and is provided substantially centrally of its upper portion with an opening 8 equipped with a tubular guide 9 through which the blanks or tubes pass from one to the other of the mills. Grouped around opening 8 there are gears l0, ll, I2 and l3'connected, respectively, to coupling heads l4, l5, l6 4 and II. The gears Ill and H are both driven by a single gear l8, which, through gears i9 and 20 and a pinion 2|, is driven by motor I. The gear 12 is driven by gear I l through an idler gear 22, and similarly the gear I3 is driven by gear l0 through an idler gear 23. The several arrows on these gears indicate their direction of rotation to properly drive spindles 24, 25, 26

and 21 connected, respectively, to the coupling heads l4, l6, l and II. The spindles 24 and 25 5 drive the cross-rolls 3 of mill I, and the spindles 26 and 21 similarly drive "the cross-rolls 3 of mill 2.

Arranged between mill l and gear box 8 there is a roller table or conveyor 28 which may be of conventional or any desired form driven by a motor 29 through the connections indicated in Fig. 1, and similarly between gearbox 6 and mill 2 there is a roller table or conveyor 30 adapted to be driven by a motor 3|.

In the operation of the tandem mill when used to' elongate and reduce the wall thickness of tubular blanks, a cylindrical mandrel is placed within a blank before the blank is passed through mill I. In Fig. 2 there is shown the forward end of a blank 32 containing a cylindrical mandrel 33 after such end has passed through mill l and is about to enter guide 9 arranged in the opening 81 of the gear box. The

spacing of the two mills is such that a blank passes completely through mill l before it enters mill 2, to the latter of which it is conveyed by roller tables 28 and 30. However, the mills are sufliciently close to each other that the forward end of the blank enters mill 2 shortly after its rear :end passes beyond mill I. Thus there is no unnecessary delay between passes, and accordingly intermediate heating of blanks is unnecessary single power unit in the manner shown and de- 35 scribed the mills may be placed sufficiently close to each other to accomplish these advantages, and there also results a material saving in the initial cost of equipment and in the cost of op- By driving the two mills with a otherwise than as specifically illustrated and described.

I claim as my invention:

1. A mill for acting upon tubular blanks, comprising a pair of cross-rolling mills arranged in tandem for successive action upon tubular blanks, each mill including helically acting cross-rolls, a gear box positioned between said mills and across the line of pass through them, and driving spindles extending from the gears in said box to the cross-rolls of each of the said mills.

2. A mill for acting upon tubular blanks, comprising a pair of cross-rolling mills arranged in tandem for successive action upon tubular blanks, each mill including helically acting cross-rolls, a gearbox positioned between said mills and across the line of pass between them and provided with an opening through it for the passageof blanks from one to the other of the-mills, and driving spindles extending from the gears in said box to the cross-rolls of each of said mills.

AUGUST P. DIESCHER. 

